1. Field of the Invention
The present invention relates to an optical recording medium and recording/reproducing from the optical recording medium, and more particularly, to an optical recording medium for storing part version information for determining whether or not recording compatibility and/or reproducing compatibility can be maintained when data is recorded and updated on/reproduced from the optical recording medium, and a method and apparatus for managing the part version information.
2. Description of the Related Art
A recording/reproducing apparatus and a recording medium comply with a specification set at any given time, but due to the addition of new functions, and improvements in the performance of functions, the specification changes. The specification is changed in order to maintain compatibility with existing recording/reproducing apparatuses or recording media, but in some cases, partial compatibility is lost in order to extend functions or improve performance.
In general, a recording medium (such as an optical disc), which complies with specifications has areas for storing a variety of information which represent the physical/logical structure and characteristics of the recording medium, and such information includes information on allocation on the physical recording medium, information on recording/reproducing characteristics, information for managing defects, information on the organization of logical recording spaces, etc.
A control information zone which records this information not only has a zone for recording this information, but also a reserved zone, which enables the addition of information related to characteristics of the recording medium or recording/reproducing apparatus in accordance with newly appearing functions or improvement in performance.
However, when a specification is revised due to these additional functions and improvements, compatibility may not be maintained. Furthermore, handling newly added information in an existing recording medium and recording/reproducing apparatus becomes another problem.
In order to solve these problems, the digital versatile disc (DVD) specification makes it a rule to record part version information on a disc. As shown in FIG. 1, this information is recorded in the first byte in the physical format information of a control data block in the lead-in zone of the disc.
FIG. 1 illustrates part version information of the existing DVD. An ordinary DVD has a lead-in zone which is a data zone for helping recording/reproducing in the starting part of a disc. This lead-in zone has a control data block zone which can record control information. This control data block zone is again divided into a physical format information zone, a disc manufacturer information zone, and a contents provider information zone.
In the existing digital versatile disc-read only memory (DVD-ROM), digital versatile disc-random access memory (DVD-RAM), etc., part version information is recorded in BPO, the first byte in the physical format information zone as shown in FIG. 1. The first byte BPO is divided into two 4-bit pieces of information, one for book type, which indicates the type of a specification book, and the other for a part version, which indicates the part version of a specification book. A disadvantage of this arrangement is that only 4 bits can be used in expressing all part versions, thus only limited versions can be expressed. That is, 4 bits can represent only 16 different part versions which are presented in the form of n.x.
Meanwhile, when a disc which can record/update or reproduce data is installed in a recording/reproducing apparatus, the part version in a physical format information zone is read and then it is determined whether or not the part version can be recorded/updated or reproduced in the recording/reproducing apparatus. Such a determination can be made because the drive of the apparatus has the part version which was a base in designing the recording/reproducing apparatus, and the drive also has information on part versions that have compatibility with the recording/reproducing apparatus (among all part versions that had been known until the recording/reproducing apparatus was made).
This arrangement is disadvantageous because the part version shown in FIG. 1 only contains part versions that had been in existence at the time the corresponding recording medium was made, and therefore may not be compatible with part versions revised after the time of manufacturing.
The same holds true for information on the physical format information zone. When new data is recorded (due to revision) in a reserved zone, or the physical format information zone, it is unclear whether the recording/reproducing apparatus will be compatible with the revised specification.
In a normal reproduction-dedicated disc, no fatal errors (such as erasing recorded information) will occur when it is determined that a zone is a physical format information zone reserved by the specification at the time of designing the reproducing apparatus. Therefore, a method is used which ignores reserved physical formation information and the like. This is done to minimize booting time for reading or writing in a recording medium at initialization. Also, even when certain data exists in the zone, the reproducing apparatus cannot determine what operations to perform.
However, ignoring information in the reserved zones can cause problems. When the information in the physical format information zone (determined to be a reserved zone by the specification of a disc) defines other characteristics of recording/reproducing, the difference between characteristics in recording/reproducing can cause the recordation of wrong information, the loss of recorded information, updating failure, or loss of existing recorded information.
For example, when recording prevention information for data is recorded in a reserved physical format information zone, a recording/reproducing apparatus having a previous specification cannot recognize this recording prevention information, and therefore, recorded data can be erased or updated even when the user sets a protection mode by using recording prevention information.